Some problems, such as routing and wavelength assignment problem and sub-wavelength traffic grooming problem can be solved by improving a performance of an optical network with optical network optimization. The solutions of these two problems may both be considered as applications of bin-packing problem. The bin-packing problem is a classical combinatorial optimization problem, which is directed to find methods to pack all items with a minimal number of bins. In particular, taking the routing and wavelength assignment problem as an example, lightpaths indicate items, routing lengths of lightpath demands indicate volumes of the items, and each waveplane that is the copy of topology indicates a bin. In this case, the method for optimizing the optical network is to rank all lightpath demands based on a descending order of routing hop lengths of the lightpaths.
In existing technology, heuristic algorithm is generally applied to a demand sequence, when the foregoing bin-packing problem is solved by the method for optimizing optical network. In the research process, at least the following disadvantages in existing technology are found.
Because an order of lightpath demands in a lightpath demand sequence affects routing and wavelength assignment algorithm greatly, the heuristic algorithm operated once in existing technology can not guarantee to obtain an optimal result every time, thus deteriorating the effect of optical network optimization.